1. Technical Field
The present invention concerns a method of stabilizing a wind power installation. One or more embodiments of invention concern in particular a method of stabilizing the connection of a foundation section of the wind power installation to the foundation of the wind power installation.
2. Description of the Related Art
The German Patent and Trade Mark Office found the following publications in relation to the application claiming priority for this application: WO 2010/084 210 A1, DE 37 33 537 A1 and DE 10 2008 032 184 A1.
DE 20 1010 007 750 U1 discloses a strengthened foundation in which a strengthening layer of concrete is applied to the foundation, wherein there is at least one bore introduced into the foundation and extending through the strengthening layer, wherein provided in the bore is an anchor passing through the strengthening layer and projecting into the foundation, wherein the bore space remaining in the bore is filled with a hardened casting material or is substantially filled therewith and wherein the anchor is biased by means of at least one biasing element on the anchor head.
DE 37 33 537 A1 discloses a method of restoring concrete foundations on masts and the like, in which fracture zone which are formed within the foundations in the area around steel profile members serving to hold mast stems and in which water accumulates even when the top side of the foundation is covered in completely water-tight fashion is filled with plastic with displacement of the water, the plastic being injected through bores produced in the foundation.
Methods of the above-indicated kind are used in wind power installations. The need for such stabilization methods arises from the fact that the wind power installations are exposed to dynamic loadings because of changing wind directions and wind strengths. The pylons of wind power installations are typically let into a concrete foundation with a lower region which can be in the form of a foundation section. In that case the foundation section frequently comprises steel or high-strength material around which the foundation concrete hardens. That provides a force-locking connection. By virtue of the dynamic stressing of the wind power installation, possibly increased by defective installation or inadequate hardening of the foundation material, with an increasing service life of the wind power installations, the foundation material surrounding the foundation section becomes loosened and as a result movement play and cracking occurs. Ultimately the structural stability is adversely affected thereby, with the force-locking connection between the foundation section and the foundation becoming weaker. To be able to guarantee further operation of the wind power installation stabilization of the wind power installation is necessary, that is to say restoring an adequate force-locking connection between foundation section and foundation.
Methods are known which permit stabilization of the foundation of the wind power installation without the wind power installation having to be completely dismantled above the foundation. Such a method is known from DE 10 2009 022 540.4. In its essential features the method disclosed there is based on lifting the entire wind power installation by one or more lifting means, for example hydraulic presses, into the upper end position involving the movement play, of a hollow space which is formed around an anchor segment of the wind power installation. After the wind power installation has been lifted and fixed in that upper position, the hollow space beneath the anchor segment which is in the upper end position of the movement play is filled in an injection process and the lifting means are removed after the filling material has hardened.
While the above-described methods afford an improvement in the maintenance-friendliness in relation to completely shutting down operation of the wind power installation and dismantling it, there is nonetheless a considerable potential for improvement in regard to maintenance time and costs which in known installations are in the region of several tens of thousands Euros or even markedly more. Accordingly the object of the invention is to provide a method of the kind set forth in the opening part of this specification, which while involving lower costs permits stabilization of a wind power installation and at the same time minimizes the outage time of the wind power installation.